Non-visual feedback

Mobile devices are often used on the move and in other situations where the device is not in active use. These situations may call for the use of non-visual feedback, such as vibration function, to get the attention of the user.

For non-visual feedback, Harmattan devices includes a set of preset sounds (.wav) and vibration patterns (.ivt). They are located in the /usr/share/sounds/ directory, which contains two subdirectories, /usr/share/sounds/ui-tones/ for sounds and /usr/share/sounds/vibra for vibration patterns. Similarly named files are usually intended to be used together. The commonly used feedback files are:

Feedback files

File name

Description

Use

snd_warning.wav

A general negative sound sample.

For drawing attention to error messages and to ensure that the user does not automatically just press 'OK'. Can be used in combination with snd_warning.ivt

snd_information.wav

A general positive sound sample.

Used to draw the attention to a positive message or UI state change, informing the user that the device is again ready for input. Also useful when there is a long delay between when the user starts and operation and when that operation is completed.

snd_default_beep.wav

Default sound.

For general or uncertain use, for example when the content of the notification comes from an external service.

tct_warning_strong.ivt and snd_warning_strong.wav

Strong negative sound and vibration

For urgent user attention due to errors.

tct_query_strong.ivt and snd_query_strong.wav

Strong positive sound and vibration

Used to get the user attention during important and unexpected events, such as incoming chat requests, even if the device is in the pocket or bag of the user.

tct_warning.ivt

A short mild vibration

Used to notify the user of slight and quickly fixable errors, such as entering an invalid value into a text field.

Sounds and vibrations are generally slightly distracting, when encountered during active device use, so you should be careful with their implementation. An application may also feature different feedback behaviour, for example when the device has been powered off, indicating a longer period of disuse. A good rule of thumb is that if the UI is unlocked, the user is directly interacting with the device and only very little non-visual feedback - such as tct_warning.ivt - is needed.